<!DOCTYPE html>
<html lang="ch-CN">
<head>
    <meta charset="UTF-8">
    <title>三个数排序</title>
</head>
<style>
    * {
        font-size: 30px;
        text-decoration: none;
    }
</style>
<script>
    while (true) {
        let num_1 = parseFloat(prompt("请输入第一个数！！"))
        let num_2 = parseFloat(prompt("请输入第二个数！！"))
        let num_3 = parseFloat(prompt("请输入第三个数！！"))
        if (isNaN(num_1)
            || isNaN(num_2)
            || isNaN(num_3)
            || num_1 === null
            || num_2 === null
            || num_3 === null) {
            alert("请在输入框内输入数值！！！")
        } else {
            let temp
            for (let i = 1; i <= 2; i++) {
                if (num_1 < num_2) {
                    temp = num_1
                    num_1 = num_2
                    num_2 = temp
                }
                if (num_2<num_3){
                    temp = num_2
                    num_2 = num_3
                    num_3 = temp
                }
            }
            document.write(num_1+">"+num_2+">"+num_3)
            break
        }
    }
</script>
<body>
</body>
</html>